1976 30 'Trojan Sportfish Repower Decisions

Discussion in 'DIY Marinizing' started by AggieBoater, Nov 13, 2004.

  1. AggieBoater
    Joined: Nov 2004
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    Location: Kemah, TX

    AggieBoater Junior Member

    Ok, I aquired a 1976 30' Trojan Sportfish this year. The guy that I got it from stripped everything out of the boat and was going to do a complete build back to show off the work of his company. Well his wife wanted more of his time and after he had spent lots of time and money changing bulkheads and purchasing lots of high end parts decided that he just didn't have the time to finish the project.

    The boat came with twin 318's. However, they were ruined so they were stripped out of the boat before I received it. The prop shafts were replaced with new 1" stainless shafts and HS drippless packings. The previous owner was going to just go back with gas 5.7L's. I would like to go diesel due to reliability and economy, but have no idea where to start deciding which diesels to use. I keep hearing problems, but no recommendations. I keep hearing that diesels are too heavy, too bulky, the prop shafts are too small, the deck will have to be raised to clear the engines, etc.

    I cannot afford new marine diesels. My dad had marinized a truck diesel for a shrimp boat he had owned before I was born and had lots of success with it. I would love to do the same. I want to get a automotive or industrial engine and cross it over. I may be interested in getting used marine diesels, but I keep getting the same problems.

    I would love to listen to any advice that is given about my project.
     
  2. Corpus Skipper
    Joined: Oct 2003
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    Location: Corpus Christi TX

    Corpus Skipper Hopeless Boataholic

    Get rid of the inboard shafts and convert her to a single diesel stern drive for the ultimate in speed and economy. But only if you intend to run the boat a LOT. Otherwise it's much more cost effective to go with those new 5.7s. 1" shafts are too small for diesels, so you'd have to change them, struts, stuffing boxes......
     
  3. Corpus Skipper
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    Location: Corpus Christi TX

    Corpus Skipper Hopeless Boataholic

    Just saw that you're from Kemah, if you're going to fish offshore much I know you have a LONG run, diesel may be the best option for range, but again, only if you're going to run it a LOT!! :D
     
  4. jav
    Joined: Mar 2004
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    Location: MA

    jav Junior Member

    Aggieboater,

    I have Trojan F-32 that I converted to diesel. I looked at many options to reduce cost but found that marinizing a non-marine diesel was significantly more expensive than buying a used marine diesel. In the end, both are used engines. You may find otherwise but be careful as marine engines (unlike automtive or truck engines) are under substantial loads all the time.. there is no substantial coasting or going down hill on the water.

    Having said that, you should consider what you want to do with the boat and select power based on that. There are lots of reasonable diesel options with good power to weight ratios that should fit (yanmar and volvo come to mind). There are also many that might be tight or impossible like the cummins 6BT(size wise?) or detroit larger detroits (weight wise?). The process is doable and rewarding but there is allot involved with doing it right... I've done it and I'm still learning. The hidden costs are many but I don't regret doing it as I have achieved my goals (20 knot cruise and better fuel economy).

    If you have any questions, I'm not an expert by any means but what I've learned, I'll be glad to share.
     
  5. AggieBoater
    Joined: Nov 2004
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    Location: Kemah, TX

    AggieBoater Junior Member

    I found specs on a Bert 30 that they made from 1981-83. It's the same hull shape, but had a smaller flybridge and cabin. It came origonally with 454's and then they re-powered with 300hp Yanmars. Might be willing to move some bulkheads for that. hehehe.....No but seriously. I do have a long distance to drive to reach good fishing grounds, so milage per tank is improtiant. Also, I don't like single screw boats or sterndrives, so that option is out. Detroit's are too heavy. Yanmars are probally the way I would like to go. My Morgan has a Volvo, and it runs great, but parts are very expensive. So I'm going to have to change the shafts and stuff huna,...well so be it. Heard I might anyway. Any idea where I might be able to find good pricing for used diesels? Apart from size and hp what specs might I need to keep an eye out for?
     
  6. kapnD
    Joined: Jan 2003
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    Location: hawaii, usa

    kapnD Senior Member

    Aggie, Boatdiesel.com has hours of good reading you need to do.
     
  7. jav
    Joined: Mar 2004
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    Location: MA

    jav Junior Member

    Aggie,

    just a couple of comments.

    I like my boat alot but be careful comparing an early vintage Trojan to a Bertram, they are vastly different. The classic F series had a modified V hull with failry shallow transom deadrise (around 8 degrees) where most sub 33 foot Berts were true deep V's with around 20 degrees or more at the transom. The international series Trojans are more comperable bottom wise. I'm not positive on the F-30's seakeeping abilites but I would not take my F-32 way offshore if the weather was expected to be anything but excellent. It may be just fine but I don't beleive our boats were originally intented for that use, (the Bertrams were). Mind you, I haven't been out in huge seas and for the most part my boat has preformed very well. However, it does not like a following sea and unless you can keep the speed up, it can be a handful even in moderate seas.

    As far as finding diesels, Boatdiesel.com is excellent (thats where I found mine). Marineengine.com and ebay also have some listings.

    Lastly, yes, Vovlo parts are expensive but Yanmar is not known for cheap parts either. Volvo's are relatively cheap to buy where Yanmars command quite a premium as they are more desireable than the Volvos. (I actually find the Volvos easier to work on and much less complex). My boat is larger heavier than yours and cruises at 20 knots while burning less than 15 GPH total with twin 200 HP engines. I would think that same setup would do even better in a 30 footer. I do prefer the smoothness of the 6 cylinder over a 4 cylinder diesel but many 4 cylinder diesels produce more than 200 HP these days and due to size may be a better fit.

    hope this helps, Good luck.
     
  8. AggieBoater
    Joined: Nov 2004
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    Location: Kemah, TX

    AggieBoater Junior Member

    Well unless you have a canoe back sailboat, no boat likes following seas. I'm a bi-polar boater, I love sailing as much as powerboating. My sailboat has a Volvo, and your right about ease of working on. It's very simple compared to Yanmars of similar hp size, also runs much much quieter. However, it also weighs several hundered pounds more. For a 25hp I think that's quite a bit. I'll start on marinediesel.com. Thanks for the info.
     
  9. PowerTech
    Joined: Feb 2005
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    Location: FL,Keys

    PowerTech Senior Member

    Yanmar

    I have repowered quite afew boats with 4 and 6 cylinder yanmars that used to have gas engines.We use the the 6LP to replace big blocks,and the 4LH to replace small blocks.There is allways a performance gain over the old gasers.6 to 8 knots. And you dont need those huge feul tanks.The 4LH-STE is a 240 H.P. 4 banger that out runs the 350 chevy motors good. It would probobly flat out smoke a 318.I would like a 1.25" shaft with that one though.A 4LH-DTE 170 H.P. would be a nice little motor you could use your shafts with.All of these motors run up to 3800-4000 RPM shaft size is not sutch a big deal on these high spiners like it is on the low grunting big diesels.Some friendly advice don,t bother with a homemade conversion or some kind of V8 truck conversion like mercruser or marine power you would be beter of with a new small block chevy than one of those things.Good luck
     
  10. AggieBoater
    Joined: Nov 2004
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    Location: Kemah, TX

    AggieBoater Junior Member

    I looked at the engines that you specified....could work. At this point I'm almost ready to drop a couple 350's in the thing and turn it to not have to deal with the thing anymore. Puting diesels in it has turned into a huge battle of he said/she said, and no one with anything more than "I've been at this for x number of years and the other guy doesn't know what their talking about." I think I'm going to ignore the boat for a year or so and just spend money that should go elsewhere on slip rent until I have proper time and funds to adress it. New diesels are the easiest way with diesels, but too expensieve for the value of the boat. Old diesels just dont have the power to weight/size ratio to get the job done without major mods plus needing major overhauls. Long block 350's are easy to come by and cheap.
     
  11. captainrmw
    Joined: Mar 2008
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    Location: florida

    captainrmw Junior Member

    update on the conversion

    I just got a 30' Trojan "clean machine" sport fisher. Has no engines. Thought I would putin a used pair of yanmar 4lte rated at about 140 hp. The boat had chryler 318's at about 225 hp. Anyone has any thoughts or suggestions?

    Thanks!
     
  12. ezeb1473
    Joined: Mar 2008
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    Location: Long Island NY

    ezeb1473 Junior Member

    I have a 77 30ft sport and looking at the GM 6.2l diesels. From what I am gathering being that they are a high RPM diesel (cruise 2200) that not much more than a prop change would be necessary. Nothing involved with the conversion if making it a fresh water cooled engine. They fit in the same space as a v-8. Just have to add return line for excess fuel from the injector pump. They are none turbo. Manifolds are available from Osco and others. Just my 2 cents. Any feed back?
     
  13. captainrmw
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    Location: florida

    captainrmw Junior Member

    thanks ezeb1473 for your post.Are the GM6.2l engines that you are pulling from trucks to marinize? I have been told that the Yanmar engines while good ones are very expensive in parts and that I should think about getting the Cummins 5.9l. Please keep in touch, I would like to exchange ideas on this issue.
     
  14. ezeb1473
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    Location: Long Island NY

    ezeb1473 Junior Member

    The cummins 5.9l or even the 3.9l were my first choice. However the cost for the conversion for me is cost prohibitive. The kit with water cooled turbo and such is appprox. $5000. Plus they are a low rpm engine and with the torque I am back at changing struts, shafts etc. The GM 6.2L are non-turbo. Exhaust manifold are on the same cost as standard v-8 cost. With a fresh water cooling system no work on that aspect is done. Size and weight (approx. 878lbs) are almost the same a a v-8. Although the hp is only around 170 hp it has the torgue to swing a some what larger wheel while not needing to change shafts. There also are companies that have been marinizing them and they do work. And if you want to make it serpentine belt conversion, that is available also. I was just planning on running 3 inch exhaust on each side to a 5 y-pipe. Just my 2 cents.
     

  15. captainrmw
    Joined: Mar 2008
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    Location: florida

    captainrmw Junior Member

    thanks for the update, what do you think it would end up costing you for the conversion. please let me know how you make out with your project.
     
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